Finding the Fourth Proportional to 72,707.55, 109,063.89 and 20,121

Step by Step Solution

1. Step 1: Write the proportion equation
   72,707.55 : 109,063.89 = 20,121 : x
2. Step 2: Convert to fraction form
   72,707.55/109,063.89 = 20,121/x
3. Step 3: Cross multiply
   72,707.55x = 109,063.89 × 20,121
4. Step 4: Simplify right side
   72,707.55x = 2,194,474,530.69
5. Step 5: Solve for x
   x = 2,194,474,530.69/72,707.55
6. Step 6: Final answer
   x = 30,182.21